Probe pin

Abstract

A probe pin includes a coil spring, a first plunger, a first end of which is inserted from a first end of the coil spring into the coil spring and a second end of which is exposed to outside of the coil spring, and a second plunger, a first end of which is inserted from a second end of the coil spring into the coil spring to be in contact with the first end of the first plunger and a second end of which is exposed to the outside of the coil spring. The second plunger includes at least one elastic arm extending from the second end of the second plunger, and a touch portion is provided at a leading end of the elastic arm and displaceable in a direction intersecting an axial center direction when pressing force in the axial center direction is applied to the touch portion.

The invention claimed is: 
     
       1. A probe pin comprising:
 a coil spring; 
 a first plunger, a first end of which is inserted from a first end of the coil spring into the coil spring and a second end of which is exposed to outside of the coil spring; and 
 a second plunger, a first end of which is inserted from a second end of the coil spring into the coil spring to be in contact with the first end of the first plunger and a second end of which is exposed to the outside of the coil spring, wherein 
 the second plunger includes at least one elastic arm extending from the second end of the second plunger, 
 a touch portion is provided at a leading end of the elastic arm and displaceable in a direction intersecting an axial center direction when pressing force in the axial center direction is applied to the touch portion, and 
 a step portion is provided along an edge of a surface of the at least one elastic arm of the second plunger. 
 
     
     
       2. The probe pin as claimed in  claim 1 , wherein
 as a point of action, the touch portion is disposed between a supporting point provided in a base portion of the elastic arm and an axial center. 
 
     
     
       3. The probe pin as claimed in  claim 1 , wherein
 the touch portion provided at the leading end of the elastic arm extending from the second end of the second plunger is displaceable toward the axial center by pressing force in the axial center direction. 
 
     
     
       4. The probe pin as claimed in  claim 1 , wherein
 the second plunger includes a pair of the elastic arms which are symmetrically disposed. 
 
     
     
       5. The probe pin as claimed in  claim 1 , wherein
 a curved connection portion, which connects the elastic arm and the touch portion, is provided. 
 
     
     
       6. The probe pin as claimed in  claim 1 , wherein
 the touch portion has a V-shape. 
 
     
     
       7. The probe pin as claimed in  claim 1 , wherein
 the touch portion has a corrugated shape. 
 
     
     
       8. The probe pin as claimed in  claim 1 , wherein
 the touch portion has an apex shape. 
 
     
     
       9. The probe pin as claimed in  claim 1 , wherein
 the touch portion has an arc shape. 
 
     
     
       10. The probe pin as claimed in  claim 1 , wherein
 the second plunger is provided with a portion at least from the elastic arm to the touch portion of the second plunger, the portion having a trapezoidal shape. 
 
     
     
       11. An electronic device comprising a probe pin claimed in  claim 1 .